Abstract

Thin films of perovskite-structured oxides with general formula ABO3 have great potential in electronic devices because of their unique properties, which include the high dielectric constant of titanates, high-TC superconductivity in cuprates, and colossal magnetoresistance in manganites. These properties are intimately dependent on, and can therefore be tailored by, the microstructure, orientation, and strain state of the film. Here, we demonstrate the growth of cubic Sr(Ti, Fe)O3 (STF) films with an unusual self-assembled nanocomposite microstructure consisting of (100) and (110)-oriented crystals, both of which grow epitaxially with respect to the Si substrate and which are therefore homoepitaxial with each other. These structures differ from previously reported self-assembled oxide nanocomposites, which consist either of two different materials or of single-phase distorted-cubic materials that exhibit two or more variants. Moreover, an epitaxial nanocomposite SrTiO3 overlayer can be grown on the STF, extending the range of compositions over which this microstructure can be formed. This offers the potential for the implementation of self-organized optical/ferromagnetic or ferromagnetic/ferroelectric hybrid nanostructures integrated on technologically important Si substrates with applications in magnetooptical or spintronic devices.

Metal Rubber

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Terrible, horrible things can be done to this millimeters-thick patch of shimmering material crafted by chemists at NanoSonic in Blacksburg, Virginia. Twist it, stretch it double, fry it to 200°C, douse it with jet fuelthe stuff survives. After the torment, it snaps like rubber back to its original shape, all the while conducting electricity like solid metal. Any other material would lose its conductivity, says Jennifer Hoyt Lalli, NanoSonics director of nanocomposites.
The abused substance is called Metal Rubber, and, according to NanoSonic, its particular properties make it unique in the world of material chemistry